diff --git a/tests/prepare_pytests.py b/tests/prepare_pytests.py
index 9e50ea90d11462ca46c64c9c299c8911d63e7f39..64fafde1cc9ebddf94590fe0a19d6b26a320d09a 100755
--- a/tests/prepare_pytests.py
+++ b/tests/prepare_pytests.py
@@ -103,7 +103,7 @@ def main(argv):
         base_cmd += ["tests/codec_be_on_mr_nonselection"]
     base_cmd += [
         "-n",
-        "14",
+        args.numprocesses,
         "--update_ref",
         "1",
     ]